Electrical vacuum discharge device



, E. w. KELLY.

ELECTRICAL VACUUM DISCHARGE'DEVICE.

APPLICATION FILED OCT. 6, 19I9.

1,414,741, Patented May 2,1922.

EDWIN W. KELLY. 01: OAK PARK.

VECTOR LE-RAY CQRPORATION.

YORK.

Specification of Letters Pafient.

ELECTRECAL VACUUM DISCHARGE DEVICE.

Patented may 2., fizfli Application filed October 6, 1919. Serial No. 3%,623.

To all whom 1'? may Pom'crn Be it known that l. llnwm W. Knuooa citizen of the l nited h'tiites, residing at (lak Park. in the count of Cook and State of lllinois. have invented a new and useful improvement in Electrical Vacuum Discharge Devices. oi which the Following is a specification.

.monly known as oi-anodes, assistant anodes. auxiliary anodes. or designated by some other-term which distinguishes them from the main anodes. and which in fihe following description are referred to as l i.-inodes. the purpose of the bi-anode of an X-ray tube being to elin'iinate the high break-down eletrieal resistanro ot the vacuum and cause the tube to operate steadily with a eomparalively uniform electrieal resistance.

it has been the usual practice in the manufacture of Xn'ay tubes-with bi-anodes. to form an opening in the enclosing insulating shell of the tube at a point remote from the cathode and approximating the region of the anode. and securing therein. to he in communication with both the interior and exterior of the shell. :1 current, conducting member.

The [)lOViSlUD of the bi-anode fir set forth presents a number ol disadvantages. one oi" which is the necessity for the provision of the opening therefor in the enclosing shell of the tube. which requires the provision ol 3 seal at this point and the attaehment of a tubular exlension. with 'cnusevplent added 031- pense in the production of the tube and likelihood of greater service required in maintainin; the lube in operation. l nrthermore. the communiealion ol the bi-auode with the interior of the shell. and thereby its contact with the gas in the lube. all'ccts the gas in the tube in such a manner. and beyond the control of the operator, as to muse the pone sirable embodiment of my invention.

tratine quality or the X-rays emitted from the tube to vary. Also the hi-anode presenhe' a protuberance on the tube so located than itinterferes. to a moderate extent under certain ('onditions. with the use of the apparatus in connecti on with other devices. Again the iii-anode is usually connected WilJh the main anode by a spiral. current-conduct in rniember whieh presents interference in clamping the tube.

in connection with Xaay tubes my object, is to provide for the elimination of the high brealedown electriail resistance 0% the vacuum and cause. the tube to operate steadil v with a comparatively uniform electrical resistance. by means whieh will be free of the objections incident to the use of the hianode as commonly provided, as above pointed out. thereby .to avoid the provision of an opening and seal therefor in the tube shell ior such bi-anode and the reduction of lhe amount of service required in maintaining the tube in operation; to avoid a protube ance such as that above referred to; $0 avoid contaet of the gas in the tube with the bi-anode and maintain more nearly constant the penetrating quality of the X-ra'ys emit led from the tube: and other objects as will be understood from the followingdesorip tron.

Referring to the accompanying drawings, wherein l have illustrated my invention as appl-ied'to an Yin-av tube. Figure l showshy a plan view an X-ray tube constituting a cle- Figure 2 is an enlarged broken seelion taken at lhe line 2 on i i gurel and viewed in the direction of the arrow. the main anode being shown in elevation. Figure 3 is aeview of one end or" the blank from which the bianode of lhe tube is formed: and Figure 4-, an end view of the bi-a node bent to shape.

It may be stated as a preface to the. following deseription of the prelerred illustrated embodiment. of my invent-ion; that it is based upon the discovery tnatrin order to perform the. function of a. conventional loianode. it is not neeessary to provide an all dilional terminal exterior of the enclosing shell of the tube in nretallic eonduetive relation to a terminal within the shell. but, that this function may he performed by charging the outside surface of the'rnsulat ae egei I 3 nlember being located wholly exterior of said shell, said member being in electrical 15 said shell, a portion of said member extend conductive relation to said anode. ing-into such-positionas to cause the exte- 6. An electrical vacuum discharge device rior surface of-said shell, when the tube is comprising, in combination, its insulating 5 energized,"to be charged with the same 30- enclosing shell containing a cathode and an larity as that of the anode. anode the latter located in a tubular exten- 2e 5. An electrical vacuum discharge device sion on said shell, and 'a member of currentcomprising, in cdrnbination, its insulating conducting material havingahollow portion enclosing shell containing a cathode and an at which it engages said extension and pro- 10 anode, the latter located in a tubular extenvided with diverging arms which extend adsion on said shell, and a nieinber of currentj acent said shell said member being in elee 25 conducting material having a hollow portion trical conductive relation to said anode.

at which it engages said extension and provided-with, an arm which extends adjacent EDWIN W. KELLY. 

